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1
Evidence of Assessing Computational Thinking
Cynthia Selby
University of Southampton
Highfield
Southampton UK
C.Selby@
southampton.ac.uk
Mark Dorling
Computing At School
BCS, Chartered Institute for IT
Swindon UK
Mark.Dorling@
computingatschool.org.uk
John Woollard
University of Southampton
Highfield
Southampton UK
J.Woollard@
southampton.ac.uk
Abstract
Computational thinking is at the heart of the new English national curriculum for
computing. There is a range of academic and pedagogic interpretations of the
concept of computational thinking, a lack of understanding of the concepts and a
close association of the subject with writing computer code using a programming
language. Teachers might focus on a small aspect of the programme of study,
thereby neglecting the breadth of content and the broader aims. In addition, the
level descriptors associated with the curriculum have been removed creating a need
for assessment guidance. In light of these changes, this paper explores the statutory
requirements of the curriculum and the descriptions of computational thinking. It
suggests a mechanism for assessment of achievement and progression for both
computing and computational thinking.
Keywords: Computational thinking, assessment, secondary school, computer
science education, curriculum design, pedagogy
2
Introduction
From September 2014, pupils in state-maintained schools will be expected to follow
the programmes of study set out in the national curriculum document (Department
for Education (DfE), 2013b). The subjects addressed in this document include
computing. In addition, the statutory assessment framework is being removed and
the system of assessment levels is not to be replaced (DfE, 2013a).
Computational thinking sits at the heart of the national curriculum programme of
study for computing. The opening sentence states “A high quality computing
education equips pupils to use computational thinking and creativity to understand
and change the world” (DfE, 2013b, p. 188). The scope of computational thinking is
described in the first aim – “understand and apply the fundamental principles and
concepts of computer science, including abstraction, logic, algorithms and data
representation” (DfE, 2013b, p. 188). There are many different interpretations of the
concept of computational thinking. Jeanette Wing, when she first used the term,
defined computational thinking as including “… a range of mental tools that reflect the
breadth of the field of Computer Science” (Wing, 2006, p. 33).
However, there is a strong emphasis, being led by the media, implying that the new
computing curriculum focuses on “coding” (Crow, 2014; Nettleford, 2013). This
misleading message, received by teachers and parents, could have a negative
impact in the classroom. There is a danger of teachers focusing on a small aspect of
the programme of study, thereby neglecting the breadth of the subject content and
the broader aims.
Computational thinking is itself in danger of becoming a “buzz word” in the teaching
of computing. Teachers acknowledge the need to teach computational thinking but
may struggle with the various and conflicting interpretations of its nature. This may
be the result of debate by individuals and groups (Computer Science Teachers
Association (CSTA), 2011; Henderson, et al., 2007; Lu, et al., 2009; Naughton, 2012;
Wing, 2006; Wing, 2008; Yadav, et al., 2011) concerning what is and is not
computational thinking. Some of these definitions are broad, overlapping other
subjects (Bundy, 2007; CSTA, 2011). In order to facilitate incorporation of
computational thinking into classroom practices, a narrower definition is required.
Once computational thinking is defined adequately, appropriate assessment
instruments can be designed (National Research Council, 2010).
Recent developments in pedagogy have focussed upon thinking skills (Department
for Education and Employment (DfEE), 1999; Department for Education and Skills
(DfES), 2002; Wickens, 2007) as underpinning areas of the curriculum. ‘Thinking
Hats’, based on de Bono’s work (de Bono, 2000; de Bono, 2007), is a popular
approach in which pupils are encouraged to think about the way they think. The
computing curriculum is now challenging pupils to think using particular strategies for
solving problems and understanding situations, referred to as computational thinking.
3
There are a number of stages towards establishing a curriculum in which
computational thinking can be taught and then assessed. These stages are:
to establish an understanding of the current computing curriculum,
to establish the meaning of computational thinking,
to establish an assessment framework for the current computing curriculum,
and
to develop a method for evidencing the assessment of computational thinking.
Current computing curriculum
The programme of study has high-level aims in terms of the introduction of computer
science (DfE, 2013b). The following extracts illustrate learner capabilities at different
stages of primary and secondary education.
• At key stage 1 (ages 5-7), pupils should be able to “understand what
algorithms are; how they are implemented as programs on digital devices;
and that programs execute by following precise and unambiguous
instructions” (DfE, 2013b, p. 189).
• At key stage 2 (age 7-11), pupils should be able to (among other things):
“solve problems by decomposing them into smaller parts” and also “use
logical reasoning to explain how some simple algorithms work and to detect
and correct errors in algorithms and programs” (DfE, 2013b, p. 189).
• At key stage 3 (ages 11-14), pupils should be able to: “design, use and
evaluate computational abstractions …” and “use logical reasoning to
compare the utility of alternative algorithms for the same problem” (DfE,
2013b, p. 190).
• At key stage 4 (ages 14-16), pupils should be able to “develop and apply their
analytic, problem-solving, design, and computational thinking skills” (DfE,
2013b, p. 191).
These extracts demonstrate an emphasis on the progressive development of
computational thinking skills. Teachers in England, engaging with the new
programme of study, are now frequently hearing the term computational thinking and
may question what it means to them as classroom practitioners.
Along with the move toward computational thinking, there is a withdrawal from the
use of national standardised levels and level descriptors. Under the auspices of the
Department for Education (2013a), schools are now free to design their own
assessment models. There are many reasons for this move, including the
suggestion that assessment leads the teaching (Barker, 2013; Passmore, 2007;
Warner, 2008).
4
Computational thinking concepts
Jeanette Wing broadly defines computational thinking as “… the thought processes
involved in formulating problems and their solutions so that the solutions are
represented in a form that can be effectively carried out by an information-processing
agent” (Cuny, Snyder, Wing, 2010, cited in Wing, 2011, p. 20). Wing indicates that
these solutions can be carried out by any processing agent, whether human,
computer, or a combination of both (Wing, 2006). The emphasis in this statement is
on thought processes, not the production of artefacts or evidences.
Given Wing’s description of computational thinking, the next step is to decompose
that definition into a set of concepts. This work has been undertaken by Selby and
Woollard (2013). The result refines the definition of computational thinking to six
concepts: a thought process, abstraction, decomposition, algorithmic design,
evaluation, and generalisation. All of these concepts are employed in problem-
solving processes. Again, the emphasis in this list of concepts is on thought
processes, not the production of artefacts or evidences.
Computing progression pathways
Although there is some disagreement concerning at what level a computing
assessment framework should be developed, from a classroom practitioner’s
perspective, there is definitely a need for one. This section introduces the
Computing Progression Pathways and describes how it can be used to acknowledge
progression and reward performance in mastering both the computing programme of
study content and computational thinking skills.
There is some debate about whether it is important that the arbitrary values of
progression be standardised across schools. Naace (Harrison, 2014), in their
guidance, indicate “…a school approach to assessment will need to be tailored to
match their approach to the curriculum” (p. 1). Alternatively, the National
Association of Head Teachers (NAHT) propose when translating the national
curriculum into assessment criteria “… there is little room for meaningful variety, we
suggest this job be shared between schools” (2014, p. 10). Whether it is designed
by a single school or a collection of interested parties, an assessment framework is
required by classroom practitioners.
The Computing Progression Pathways (Dorling and Walker, 2014) is an example of
a non-statutory assessment framework. It was produced by a small team of authors
and reviewers, all teachers, based on their classroom experiences. It is an
interpretation of the breadth and depth of the content in the 2014 national curriculum
for computing programme of study. It includes the dependencies and
interdependencies between concepts and principles. This may help non-specialist
teachers and inexperienced teachers to understand what should be taught in the
classroom. It is publically available at this link:
5
https://www.hoddereducation.co.uk/Subjects/ICT/Series-pages/Compute-IT/Series-
Box/Progression-Pathways/Progression-Pathways-Grid.aspx.
The framework is grid-based. Five of the six strands, represented as columns, are
aligned with the range and content categories from the Computing at School
curriculum (Computing at School, 2012) and the requirements of applicants to initial
teacher training courses (DfE, 2012). These include algorithms, programming and
development, data and data representation, hardware and processing,
communication and networks. The sixth strand incorporates the more traditional
concept of information technology. This breadth affords an opportunity to view the
subject of computing as a whole, rather than the separate subjects of Computer
Science, Digital Literacy, and Information Technology. Each row represents a level
of pupil progression. Annotation of the framework suggests that key stages 1-2
cover the first four levels (pink, yellow, orange, and blue), that key stages 3-4 cover
the next four levels (purple, red, and black), and that GCSE covers the final level
(white). As an example, the purple cell under the “Hardware and Processing” strand
states that a pupil “Recognises and understands the function of the main internal
parts of basic computer architecture” (Dorling and Walker, 2014).
The colour-coded rows may aid teachers in assessing whether pupils are exhibiting
competences at different levels and in recognising achievement and attainment. In
addition, adherence to the colour-coded statements can provide standardisation
across schools as identified by the NAHT (2014). Institutions planning to use this
assessment framework with existing assessment or reporting systems may:
• assign values or levels to the coloured rows,
• agree the benchmark value, level, or entry point for a particular key stage,
• assign the benchmark value or level to the appropriate progression
statements.
The Computing Progression Pathways also affords opportunities to celebrate
achievement in computing. There is a growing interest in badges as an informal
recognition of skill, knowledge, understanding, or attitude. They are made and
awarded by commercial organisations, educational suppliers, websites, schools,
teachers, and pupils (Hamilton and Henderson, 2013; Mozilla, 2014; Radiowaves
Schools, 2014). Recognising and rewarding pupil achievement in each strand can
be accomplished via coloured digital badges. Each strand can be assigned a
separate digital badge. There may be two-tone badges for pupils working between
coloured progression levels. Currently, there are no digital badge designs for the
strands. Teachers and pupils who will be using the digital badge system are better
placed to design and create them. The process of designing and creating the digital
badges might promote learner ownership and student-centeredness (Reigeluth,
2013).
6
Evidence of assessing computational thinking
Given that computational thinking concepts have been defined (Selby and Woollard,
2013) and an assessment framework for the computing programme of study has
been proposed (Dorling and Walker, 2014), a mapping can be developed to illustrate
how computational thinking can be assessed over the full breadth and depth of the
computing programme of study.
The key to developing this mapping lies in understanding that computational thinking
concepts can be demonstrated in multiple ways. For example, decomposition is
demonstrated by pupils breaking game logic down into levels (avoid traps, climb
mountain, guess password). This can be mapped to the “Programming &
Development” strand, blue row. However, it can also be demonstrated by pupils
designing a library inventory (an inventory grid for DVDs, a different grid for books).
This can be mapped to the “Data & Representation” strand, yellow row. These
examples illustrate decomposition in terms of functionality and data structures,
across strands (breadth) and across rows (depth).
Rather than provide specific examples, tied to activities, for each statement in the
Computing Progression Pathways that illustrate one or more computational thinking
concepts, consider the meaning of the computational thinking concept and how it
might apply to the pathways’ statement. This affords the opportunity for classroom
practitioners to contextualise the pathways and computational thinking concepts in
any way they see fit.
As an example of this approach, consider the purple cell of the “Hardware &
Processing” strand of the Computing Progression Pathways. It requires that a pupil
“Understands the concepts behind the fetch-execute cycle” (Dorling and Walker,
2014). The fetch-execute cycle can be viewed as an algorithm. Understanding of
this demonstrates the computational thinking concept of algorithmic thinking.
Therefore, at a minimum, this pathways’ statement maps to the computational
thinking concept of algorithmic thinking. Once this mapping is complete, it is
possible to identify, across the breadth and depth of the programme of study, all
those activities with potential to enhance computational thinking skills.
The following table is a reproduction of the blue row (mid-range of key stage 3) of the
Computing Progression Pathways (Dorling and Walker, 2014). Each statement has
been numbered. Where applicable, the computational thinking concepts associated
with that statement have been indicated in the last column. The computational
thinking concepts of abstraction, decomposition, algorithmic design, evaluation, and
generalisation have been abbreviated to the first two letters. Care has been taken by
3 iterations of expert evaluation of the statements to avoid making assumptions
about how the teaching might afford opportunities for computational thinking rather
than strictly interpreting what is explicitly stated in the Computing Curriculum
Pathways. For example, an exercise in a classroom might afford opportunities to
identify suitability for purpose and efficiency of input and output devices. That would
7
fall into the yellow cell of the “Hardware & Processing” strand, where a pupil
“Recognises and can use a range of input and output devices” (Dorling and Walker,
2014). The teaching affords the opportunity for evaluation, although the statement
from the pathways does not indicate that it would be an evaluation-based exercise.
The teaching of the fetch-execute cycle, previously mapped to algorithmic thinking,
usually incorporates the ideas of instructions and data, which correspond to the
concept of abstraction. The teaching affords the opportunity for abstraction,
although the pathways statement does not explicitly anticipate this.
Strand Statement from the Computing Curriculum Pathway CT
Concept
A Shows an awareness of tasks best completed by humans or
computers.
Designs solutions by decomposing a problem and creates a sub-
solution for each of these parts.
Recognises that different solutions exist for the same problem.
EV
DE, AL, AB
AL, AB
P&D Understands the difference between, and appropriately uses if
and if, then and else statements.
Uses a variable and relational operators within a loop to govern
termination.
Designs, writes and debugs modular programs using
procedures.
Knows that a procedure can be used to hide the detail with sub-
solution.
AL, DE
AL, AB
AL, DE, AB,
GE
AL, DE, AB
D&DR Performs more complex searches for information e.g. using
Boolean and relational operators.
Analyses and evaluates data and information, and recognises
that poor quality data leads to unreliable results, and inaccurate
conclusions.
AL, EV
EV
H&P Understands why and when computers are used.
Understands the main functions of the operating system.
Knows the difference between physical, wireless and mobile
networks.
DE, AB
AB
8
C&N Understands how to effectively use search engines, and knows
how search results are selected, including that search engines
use ‘web crawler programs’.
Selects, combines and uses internet services.
Demonstrates responsible use of technologies and online
services, and knows a range of ways to report concerns.
AB, EV
AL, EV
IT Makes judgements about digital content when evaluating and
repurposing it for a given audience.
Recognises the audience when designing and creating digital
content.
Understands the potential of information technology for
collaboration when computers are networked.
Uses criteria to evaluate the quality of solutions, can identify
improvements making some refinements to the solution, and
future solutions.
EV
EV
EV
EV
Key Computing Curriculum Pathways
A Algorithms;
P&D Programming and Development;
D&DR Data and Data Representation;
H&P Hardware and Processing;
C&N Communication and Networks;
IT Information Technology
Computational Thinking Concept
AB Abstraction;
DE Decomposition;
AL Algorithmic Thinking;
EV Evaluation;
GE Generalisation
Table 1: Computational thinking and progression pathways in computing (Based on
Dorling and Walker, 2014)
Using this strategy of identifying computational thinking concepts associated with the
pathways’ statements enables computational thinking to be assessed using the
same framework as the programme of study. From a practitioner’s perspective,
there is no additional assessment or progression tracking required to fulfil the broad
aim of the computing programme of study to incorporate computational thinking.
Conclusion
The computing programme of study (DfE, 2013b) includes the broad aim of
incorporating computational thinking into the classroom. The subject content is
detailed in the document, but the connection to computational thinking and its
meaning is not. Removal of the statutory assessment frameworks, which did not
assess computational thinking, leaves a void in assessing pupils’ attainment. Both of
these shortcomings have been addressed in this paper. An understanding of
9
computational thinking, based on the work of Selby and Woollard (2013), has been
established. An assessment framework, the Computing Progression Pathways, has
been used to illustrate the dependencies and interdependencies between the
concepts and principles of the programme of study (Dorling and Walker, 2014). This
work has demonstrated how the Computing Progression Pathways can be used to
evidence the assessment of computational thinking directly. By using the
assessment framework to evidence progression, with its underlying support for
computational thinking concepts, it is possible for the classroom practitioner to
assess computational thinking without introducing additional complexity to the
assessment process. However, this does raise questions around the provision for
teachers of a framework for the pedagogy of computational thinking that aligns to
this assessment approach.
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